1. Technical Field
The present invention relates to a clamping assembly for use during the cutting of predetermined lengths of tire material. More particularly, the present invention relates to a cutter clamp for use in cutting predetermined lengths from an elongated strip of tire material to be formed into a tire. Specifically, the present invention is a preassembly cutter clamp that is used to clamp one sidewall section of the elongated strip of tire material adjacent an air suction manifold for assuring a uniform and even cut by the cutter.
2. Background Information
In general, tires are manufactured along an assembly line including various stages, one of which involves the proper length cutting of a predetermined length of multi-ply material to be wrapped around a tire building drum on which the ends of the length are connected, the edges of the length are turned up to form a toroidal carcass. Currently, this cutting process begins when a roll of preassembly, that is a roll of multi-ply material including layers of rubber and belts, is transported to and loaded on the server. The outermost end of this preassembly is placed on a first conveyor and moved towards a manifold and cutter unit. During this process the preassembly passes a cutter unit and stops at a predetermined point. This predetermined point is a set distance beyond the cutter and toward the drum where the set distance is the linear equivalent of the desired tire circumference. The conveyor stops and the preassembly is held in place, typically by an air suction manifold positioned adjacent to the cutter unit so as to divide the conveyor into two sub-conveyors, one of which is on each side of the manifold. The preassembly is suctioned against the air suction manifold by a vacuum provided within the manifold and effective via numerous suction holes. A cutter then severs the preassembly into a desired length, where the cutter is typically either a sharpened knife blade or an ultrasonic knife. Once the cut is performed, the vacuum is shutoff and the conveyors activated. The cut length is then removed from the conveyor and wrapped around a tire building drum for assembly into a tire where such assembly includes connection of the ends, turning up of the edges or sidewalls typically using bladders. This process is repeated numerous times until the roll is depleted whereby the plurality of preselected lengths of multi-ply material are created and transformed into carcasses.
The cut supplied by this process is often uneven and nonuniform. This is a result of various shortcomings in the process. First, due to the contours and uneven profile of the sidewall along each edge of the unrolled preassembly, the suction manifold often cannot adequately hold the preassembly in place. Specifically, the sidewall contains various nonuniform components such as raised white letters and/or a whitewall strip, which are uneven, and the sidewall might have a slight curvature outward toward the edge. Therefore, in either case, the sidewall is not easily subjected to suction at the manifold. Second, the cutter often starts at one edge of the preassembly and cuts across the preassembly to the other edge resulting in a pulling force as the knife engages the preassembly thereby providing an uneven and nonuniform cut. In the alternative, the cutter may cut the preassembly from below the manifold, either in or adjacent to the manifold, such that the cutter lifts the preassembly during cutting thereby providing an uneven and nonuniform cut.
It is well known in the art that it is desirable to make this cut as even and uniform as possible so as to provide for easier, more economical, and more reliable connection of the edges of the cut length during building of the tire. Therefore, it is desirable to improve the cutting process on the preassembly in a tire building assembly line.